The two remaining presidential candidates in Afghanistan are resuming their campaigns for next month's run-off vote. Abdullah Abdullah and Ashraf Ghani failed to secure the 50 per cent of the vote required in the first round. The electoral commission expressed concern over security surrounding the polls, scheduled on June 14. The Afghan Taliban has just launched a new offensive in different parts of the country. Al Jazeera's Imtiaz Tyab reports from Kabul.